Teleprinter for automatic telex service



Oct; 23, 1956 o. MOSER TELEPRINTER FOR AUTOMATIC TELEX SERVICE v 5Sheds-Sheet 1 Filed April 5, 1952 1956 o. MOSER 2,768,233

TELEPRINTER FOR AUTOMATIC TELEX SERVICE United States Patent TELEPRINTERFOR AUTOMATiC TELEX SERVICE Otto Moser, Bern, Switzerland ApplicationApril 5, 1952, Serial No. 280,843 Claims priority, applicationSwitzerland April 6, 1951 8 Claims. (Cl. 178-79) In automaticteleprinter service number dials like those generally used in automatictelephone service are employed for calling the desired subscriberalthough the teleprinters themselves have keys with letters and with thedigits from to 9.

This invention refers to a teleprinter for automatic service in which nospecial number dial is needed for calling subscribers inasmuch as inaccordance with the invention the teleprinter is equipped with aselector impulse generator operated by the teleprinter keys.

it is therefore an important object of the invention to provide meansaffording a greatly simplified construction and operation of ateleprinter, in which transmission means transfer the movements of thekey levers and are coordinated to the keys, whereby upon actuation of asingle key the remaining keys become inoperative by common lockingmeans.

Another object of the invention resides in the provision of meansavoiding the possibility of simultaneous actuation of several keysduring operation of the teleprinter.

These and other objects of the invention will become further apparentfrom the following detailed description, reference being made to theaccompanying drawings. The accompanying drawings represent by way ofexample one embodiment of the teleprinteraccording to the invention,wherein:

Fig. 1 shows a side view of the transmitter unit of the teleprinter(with drive means omitted), in partial section;

Fig. 2 shows a front view of the number selector impulse generator;

Fig. 3 shows a section taken along line III-III of Fig.2; i

Fig. 4 shows a section taken along line IVIV of Fig. 2;

Fig. 5 shows an elevational view of the number selector impulsegenerator, as seen from the right of Fig. 2;

Figs 6 and 7 show the circuiting of the electrical parts of the numberselector impulse generator.

The number selector impulse generator, hereinafter sometimes callednumeral impulse generating meansfis mounted on a cast frame 1 attachedto the side walls'2 and 3 of the transmitter unit. The cast frame 1,extending parallel to the front of the transmitter unit, has twoforwardly directed brackets 1a and 1b. In these brackets is mounted thedrive shaft 4, to which, during operation, a torque is continuouslytransmitted inthe direction'indicated by arrows by the drive motor via afriction clutch (not shown in the drawing), and on these brackets is Ifurther journalled the trigger or release shaft 5. On the drive shaft 4,between the two brackets 1a and 1b, ten control cams 6 (only three areshown in Fig. 1) are rigidly mounted side by side, each associated withoneof the numeral keys 1, 2, 9, 0. Each cam is provided with a spiralgroove whose turns are divided .into two groups. The number of turns inthe inner group 6a corresponds to the number of numeral selectingimpulses to be emitted with the corresponding numeral key.

ice

2 The number of turns in the outer group 6b is the same for all cams.Each pair of groups of turns 6a and 6b is joined by a portion of groove6c with increased pitch (sharp transition). The inner approach to thegroove is marked 6d and the end of the groove 6e (Fig. 4).

Each cam 6 is associated with a two-arm transmission lever 7 freelyrotatable on the trigger shaft 5. One arm 7a of this transmission leveris provided with a perpendicularly set and pointed style or follower 7b,which is guided along the groove as the corresponding cam 6 revolves. Toprevent the style 711 from escaping from the groove during operation,each transmission lever 7 is provided with an abutment 22 attached tothe cast frame 1. The same arm 7a has a spring 8 attached which drawsthe transmission lever and style towards the center of the cam 6 andagainst the latter. All springs 8 are hooked to a continuous bar 9. Eachtransmission lever 7 operates in conjunction with a trigger or releaselever 10 having a hub 10a and a tab 1012. All triggers 10 arenon-rotatably and alignedly mounted on the trigger shaft 5.

11 designates one of the numeral keys of the teleprinter, simultaneouslyserving as number transmitter key in number selection. It is mounted onone end of a bell crank 13 rotatable on a pivot 12, whose downward arm13a, when the key 11 is depressed, acts on the arm 7c of thetransmission lever 7 so that the style 7b approaches the groove entrance6d. 7

Brackets 1a and 1b of frame 1 are each prolonged at their lower portionswith straps 14 and 15 respectively, rotatably mounted on the triggershaft 5 and fastened to brackets 1a and 1b with screws 16 and 17respectively passing through oblong holes in the straps. The straps 14and 15 bear a rotatably mounted pawl shaft 18 parallel to drive shaft 4and trigger shaft 5, as well as the aforesaid spring bar 9. On the pawlshaft 18, ten pawls 19 are rotatably mounted, serving to lock therespective numeral keys actuated. For this purpose, the pawls 19 areprovided with projections 19a acting in conjunction with the upper edgesof extensions 13b on arms, 13a of the corresponding bell crank 13. Thehubs 19b of the pawls 19 have radial slots 19c occupied by pins 20 fixedin the pawl shaft 18 to restrict the range of rotation of the pawls 19.The pawls 19 are held in one angular position by springs 21.

A pin 23 on bracket 1a of frame 1 bears two rotatably mounted checklevers 24 and 25 (Figs. 1, 2) acting in conjunction with discs 26 and27, respectively, fixed on the drive shaft 4. The upper arms of thecheck levers have projections 24a and 25a respectively, engaging notches26a and 27a in the discs, and are thus able to prevent rotation of thedrive shaft 4. A spring 28, when the impulse transmitter system is atrest, holds check lever 25 in engagement with disc 27. Check lever 24 isalso subject to the action of a spring 29, and is controlled by a cam 30mounted on the trigger shaft 5 and having an upper curve 30a and a lowercurve 301) acting in conjunction with a pin 31 attached to the lower arm24b of the check lever 24. At rest, pin 31 lies against the upper curve30a, so that the check lever 24 is out of engagement with the disc 26for the time being. Cam 30 also bears a rotatably mounted roller 32. Thelower arm 25b of check lever 25 has a track 250 for the roller 32.Alongside the cam 30 a fixed lever 33 is also provided, subject to theaction of a spring 34 which holds the trigger shaft 5 in an initialposition, with the circumference of the roller 32 resting on the track250. The pawl shaft 18 carries a fixed crank 35 to which a rod 36 isattached under the action of a spring 37 acting on crank 35 and hookedto the bar 9, so that at rest, the said rod abuts on the lower tip 25dof the check lever 25, thus likewise determining theinitial position ofthe pawl shaft 18. An-

J other lever 38 fixed on pawl shaft 18 acts in conjunction with a lever39 fixedly attached to the trigger shaft 5, as will be explained below.

In the location of the bracket 1b, the frame 1 also has an arm Is towhich the sets of contact springs comprising spring contacts 40-45 areattached (Figs. 2, The pair of spring contacts 40, 41 making the impulsecontact i (Fig. 7) is controlled by an impulse disc 46 mounted on theend of the drive shaft 4. For this purpose, the spring contact 40 isprovided with a projection 40a by which the impulse disc 46 lifts itperiodically as the drive shaft 4 revolves, so that the impulse contacti is opened twice during one revolution of the impulse disc 46. The pairof spring contacts 42, 43 forms the bypass contact k (Fig. 7) tosuppress supernumerary impulses. This is controlled by a switch lever 47fixed to the trigger shaft 5 and having a beveled projection 47:: at theend, so that when revolved it presses spring contact 43 against springcontact 42 after a certain angle of rotation. In addition, there is asafety contact s (Fig. 6) whose purpose will be described below andwhich consists of the pair of spring contacts 44, 45. At rest, anotherswitch lever 49 rotatable on the trigger shaft 5 and clamped to switchlever 47 in an adjustable angular position relative to the latter bymeans of screw 48 keeps the safety contact s closed. However, as soon asthe trigger shaft 5 is turned, the switch lever 49 slides off the springcontact 44, which consequently breaks away from the contact 45.

The number selector impulse generator whose structure has been describedabove is brought out of rest condition into a condition preparatory tonumber selection by means of the call key 50. The call key 50 and allparts of the number selector impulse generator that are displaced whenthe call key is operated are shown in preparatory position in thedrawing.

The key 50 is set on a bar 51 slidably and vertically mounted in abearing 54 attached to the outside of the side wall 2 of the transmitterunit by means of screws 52 and 53. The lower end of the bar 51 is actedupon by the opposing compression spring 55. The bar 51 is articulated toa lever 57 rotatable on a pivot 56, its motions being transmitted by atension member 58 to a crank 59 which in turn is rotatably mounted onpivot 60 on a bracket 61 likewise attached to the outside of the sidewall 2.

The crank lever 59 acts in conjunction with an arm 25e of check lever 25so that upon depression of the call key 50, the crank 59 forces the arm25 downward, whereby the check lever 25 is disengaged from the disc 27.As a result of this movement of the check lever 25, the track 250 sochanges its position that the trigger shaft 5 is able to rotate througha small angle under the action of spring 34. At the same time, the cam30 rotates far enough so that its lower curve 30b comes opposite thepin. 31. The check lever 24 consequently drops into place, itsprojection 24a engaging the notch 26a in disc 26, whereby check lever 24assumes the function of check lever 25. This change of place of the twocheck levers 24 and 25 is simultaneous, so that the drive shaft 4cannotbe driven by the drive motor for the time being. At the same time,the tip 25d slips off the rod 36, so that the pawl shaft 13 is rotatedunder the action of spring 37 until lever 38 touches lever 39. Thus thenumber selector impulse generator has been brought into the preparatorycondition in which it is seen in the drawing.

Lever 57 is extended by a prolongation with tab 57a acting inconjunction with a projection 62a on a pawl 62 by means of which theactuated call key 50 and all parts displaced by it are locked. The pawl62 is held in locking position by a spring 63. The locked call key 50and number selector impulse generator are released, after completion ofnumber selection, by means of an electromagnetic relay 64 whose armature65 is articulated by a bar 66 with pawl 62, so that when relay 64-isactuated, the attracted armature 65 disengages the pawl from tab 57a oflever 57 against the force of spring 63.

Of the actual transmitter of the teleprinter, the drawing (Fig. 1) showsonly the more essential parts. A detailed description of the same is tobe found in U. S. Patent No. 2,651,676.

The control means associated with the current or code impulsecombinations to be emitted and controllable by means of the severalcharacter keys are impulse discs 67, of which only one is visible inFig. l, with a lateral milled groove. They are fixed on a common shaft68 driven by the aforesaid drive motor and executing one revolution uponactuation of a character key. Each of the impulse discs 67 acts inconjunction with a follower lever 69 pivoted on shaft 70 and providedwith a guide pin 71. Upon actuation of a character key, thecorresponding follower lever 69, in manner to be described below, entersthe said groove and executes a reciprocating motion upon ensuingrotation of the impulse disc 67, which motion is transmitted to thetransmitter contact system, not shown, via a bar 73 common to allfollower levers and connected to lever 72.

The transmitter unit is also provided with a device containing, firstly,means associated with the several character keys for transmission oftheir motion to the corresponding control means, and secondly, a lockingdevice common to all of the character keys, which locking device, uponactuation of one character key, automatically locks all the others, andprevents simultaneous actuation of several character keys. This device,for each row of character keys, has a U-shaped rail 74, open upwards andwith upwardly directed legs. These rails are so arranged that the bellcranks 13 of a row of keys have their downward extensions 13b betweenthe two flanges of the corresponding rail, which limits the swing of thebell cranks 13. In the rails 74 and an additional rail 75, transverse totheir longitudinal direction, there are longitudinally displaceable bars76 associated with the individual character keys, which bars are inloose mechanical connection with the bell cranks 13 and with thefollower levers 69. The bar 76, upon actuation of key 11, transmits themotion of bell crank 13 to the follower lever 69, and after completionof impulse emission, is returned by the latter to its initial position.

The locking device comprises an additional set of bars 77 associatedwith the individual character keys and displaceably mounted in the rails74 and 75, which bars act in conjunction with a ball lock as known inthe art of typewriter design. This comprises the cage formed by thecavity in rail 75, with balls 78 movable therein, their lateral playbeing taken up upon entry of a bar 77. The bar 77 abuts loosely againstthe extension 13b of the bell crank 13 under spring pressure. The springpressure is supplied by a spring 79 disposed upon bar 77 and acting on acollar 77a thereof.

Fig. 6 diagrammatically shows the circuit for the trigger relay 64. Inaddition to the trigger relay, this ineludes source of current 80,safety contact s, and additional contact st. operable by means of thelock key 81 of the teleprinter. This diagram shows that the call key 50cannot be unlocked, nor therefore the number selector impulse generatorstopped, by actuation of the lock key 81, during emission of a numberselector impulse sequence, since during that operation the safetycontact s is always open.

Finally, Fig. 7 shows the circuiting of the impulse contact i and thebypass contact k, which are connected in series with the subscriber linevia terminals 82.

The operation of the teleprinter in number selection is as follows: Upondepression of the call key 50, the numeral impulse generating means ismechanically pre pared for ensuing number selection, as has beendescribed above. The numeral impulse generating means is thereby placedin the condition represented in the drawing. At the same time, byotherwise known means (not shown),

the first preselector' in the teleprinter station is actuated.

To select the subscriber number, one of the numeral -keys 11 of thetransmitter unit is depressed. This actuates the control system'associated with it, the lower arm 13a of hell crank 13 acting on arm 70of transmission lever 7 and swinging it so that the style 7b is moved upfrom the center of cam 6 to the groove entry 6d of the latter. At thesame time, switch lever 49 leaves spring contact 44 so that the safetycontact s is opened. In the course of its motion, the transmission lever7 carries along the trigger 10 by its tab 10b, whereby the trigger shaft5 is rotated clockwise (Fig. 1). The corresponding rotation of cam 30causes the pin 31 to be picked up on the upper curve 30a of the cam,thereby swinging the check lever 24 against the force of spring 29, sothat the'projection 24a disengages. from the notch 26a of the disc 26.In this way, the drive shaft 4 is unlocked, so that it begins torevolve.

Upon rotation of the trigger shaft 5, lever 39 draws away from lever 38,thus also releasing the pawl shaft 18. The latter now revolves under theaction of spring 37 upon lever 35, so that the pawls 19 move downwardand the actuated numeral key 11 is locked by its associated pawl 19, theprojection 19a catching the upper edge of the extension 13b of bellcrank 13. By such locking of numeral key 11, completion of the initiatedprocess of selection is ensured. The clearance of pins 20 in slots 190of pawl hubs 19b is necessary to prevent premature release of the lockedactuated numeral key in case, during the process of selection, motion ofpawl shaft 18 should inadvertently be produced by means of some othernumeral key.

Upon depression of numeral key 11, the transmitter of the teleprinter issimultaneously started via bar 76, produces the code impulse combinationsymbols corresponding to the numeral selected, and thereby controls thereceiver of the calling station, so that the number selected is printedon the control copy. By suitable circuiting procedures, the code impulsecombinations are prevented from reaching the subscriber linesimultaneously with the number selection impulses. Subsequently, thebell crank 13 of the actuated character key 11, by means of itsextension 13b, thrusts the bar 77 between the balls 78 of the ball lock,so that all other numeral keys are locked.

The revolving drive shaft 4 now produces emission of the numberselection impulse, the impulse contact i being periodically opened andclosed by the impulse disc 46. The number of impulses thus emittedcorresponds to the number of turns in the group of groove turns 6a; Thetransmission lever 7 is guided by the style 7b projecting into thegroove. Upon transition of the style 7b from the group of turns 6a tothe group of turns 6b along the portion of groove 60, the transmissionlever 7 swings more rapidly. The trigger 10 transmits this motion viatrigger shaft 5 to switch lever 47, which at that moment actu-ates thespring contact 43, whereby the contact k is closed and the impulsecontact i is bypassed (Fig. 7), so that the impulse contact i, which isstill actuated by the impulse disc 46, will not carry any additionalemitted pulses, despite further rotation of the drive shaft 4. The groupof turns of groove 6b, which is the same for all cams 6, ensures thesame selection interval for all digits between two successive selectoroperations. At the end of the group 6e, the style 7b is lifted to thesurface of the cam 6. This presses the transmission lever 7 far enoughto one side so that, under the action of spring 8, it returned to-itsinitial position along the outside of .abutment 22. At the same time,the trigger 10, under the action of the spring 34 attached to lever 33on trigger shaft 5, is also turned back, whereupon the check lever 24with pin 31 drops back on the lower curve 30b of cam 30 and stops driveshaft 4 after the last revolution by means of its projection 24a,engaging the notch 26a in disc 26. Upon return of the trigger shaft 5,the lever 39 strikes lever 38 a blow which causes the pawl shaft 18 tolift the pawls 19 briefly so that the locked character key 11 isreleased. Further, switch levers 47 and 49 move back to their initialposition, opening the bypass contact k and closing the safety contact s.

Number selection can now be continued; that is, the key corresponding tothe next digit .can be depressed. Upon completion of number selection,the relay 64 is actuated by an impulse transmitted from the teleprinterstation, so that the call key 50 and the mechanism associated with itare released and the number selector impulse generator is therebyreturned to rest position. Release can also be eifected by means of lockkey 81 during number selection, between two selection operations. Bythis means, the arm 25e of check lever 25 is relieved from the pressureof crank lever 59, so that the check lever 25 engages the disc 27 underthe action of spring 28. The motion of check lever 25 is transmitted tocam 30 via the track 25c on the lower arm 25b of the check lever and theroller 32, which cam, by rotating accordingly, takes the check lever 24out of the way of the disc 26. At the same time, the rod 36 is caught bythe tip 25d of check lever 25, thus fixing the pawl shaft 18. Thisreliably prevents the pawls 19, upon deflection of check lever 24 withnumber selector impulse generator not in use, from dropping readily andlocking any act-u ated character keys.

Various changes .and modifications may be made without departing fromthe spirit and scope of the present invention and it is intended thatsuch obvious changes and modifications be embraced by the annexedclaims.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent, is:

1. In an automatic teleprinter having a keyboard; a rotatable mainshaft, control means coordinated with and arranged for selectiveactuation by one of said keys, impulse generating means coordinated withand arranged for selective actuation by said one key and includingcontact means responsive to said control means for transmitting aplurality of current impulses corresponding to said one key, saidcontrol means and said impulse generating means being operativelyconnected with said main shaft, .an oscillatable release shaft spacedfrom said main shaft, motion-transmitting means connected with saidrelease shaft and actuatable by said control means for oscillating saidrelease shaft, and locking means disposed between said release shaft andsaid main shaft, said locking means being rendered inoperative forpermitting rotation of said main shaft in response to oscillation ofsaid release shaft by said control means.

2. An automatic teleprinter according to claim 1, wherein said controlmeans includes guide-groove means having an inlet and an outlet thereto,said motion-transmitting means comprising a lever pivotally supportedintermediate its ends on said release shaft and actuatable at one endupon depression of said one key for operative engagement of its oppositeend by said guide-groove means, and a release element secured to saidrelease shaft and operatively engageable by said lever for transmittingmovement to said release shaft.

3. An automatic teleprinter according to claim 2, including means forpreventing disengagement of said lever from said guide-groove means, andspring means for restoring said lever and said release element to theirrespective inoperative positions.

4. An automatic teleprinter according to claim 3, wherein saidguide-groove means is provided with a predetermined plurality ofconvolutions in accordance with the number of impulses desired to betransmitted.

5. An automatic teleprinter according to claim 3, wherein said controlmeans is provided with additional guide-groove means continuous withsaid first-mentioned guide-groove means, said impulse generating meansincluding short-circuit contact means, said release lever being providedwith tripping means for closing said shortcircuit contact meansresponsive to engagement of said lever by said additional guide-groovemeans, whereby said impulse generating means is rendered inoperativeduring a minimum interval of time pending locking of said main shaft.

6. An automatic teleprinter according to claim 2, wherein saidguide-groove means is provided with a predetermined plurality ofconvolutions in accordance with the number of impulses desired to betransmitted.

7. An automatic teleprinter according to claim 2, wherein said controlmeans is provided with additional guide-groove means continuous withsaid first-mentioned guide-groove means, said impulse generating meansincluding short-circuit contact means, said release lever being providedwith tripping means for closing said shortcircuit contact meansresponsive to engagement of said lever by said additional guide-groovemeans, whereby said impulse generating means is rendered inoperativeduring a minimum interval of time pending locking of said main shaft.

8. An automatic teleprinter having a keyboard with separateletter-designating keys and with numeraldesignating keys; control meanscoordinated with and arranged for selective actuation by said separatekeys, contact means responsive to said control means for transmittingcode impulse combinations corresponding to said designated letters andnumerals, numeral impulse generating means linked for movement with saidnumeraldesignating keys, means normally locking said numeral impulsegenerating means, so that upon actuation of a numeral-designating keyonly code impulse combinations are transmitted, and additional controlmeans arranged for actuation by said numeral-designating keys fortransmitting by said generating means a plurality of numeralselectingimpulses corresponding to said designated numetals.

References Cited in the file of this patent UNITED STATES PATENTS1,100,413 Wotton June 16, 1914 1,814,236 Wusteney July 14, 19311,954,170 Gibbs et a1. Apr. 10, 1934 1,965,121 Kardorfi July 3, 1934

